1. Field of the Invention
This invention relates to a zoom lens suitable for compact digital still cameras and digital video cameras (which are hereinafter generically called digital cameras) and an image pickup apparatus provided with this zoom lens and an image sensor, such as a CCD or CMOS.
2. Description of Related Art
It has been required that the zoom lens adopted to the digital camera is wide in angle of view, high in magnification, low in cost, and compact in design. As a zoom lens satisfying such requirements, one which includes, in order from the object side, a first lens unit with positive refracting power, a second lens unit with negative refracting power, a third lens unit with positive refracting power, a fourth lens unit with positive refracting power, and a fifth lens unit with positive refracting power so that an optical path is changed in the first lens unit is known, and an example of this zoom lens is disclosed in Japanese Patent Kokai No. 2004-264786. Such a zoom lens realizes a high variable magnification ratio of about 2.5 and favorable optical properties and is capable of attaining a slim design of the digital camera adopting the zoom lens.
As another zoom lens satisfying these requirements, one which includes, in order from the object side, a first lens unit with positive refracting power, a second lens unit with negative refracting power, a third lens unit with positive refracting power, a fourth lens unit with positive refracting power, and a fifth lens unit with negative refracting power so that the optical path is changed in the first lens unit is known, and an example of this zoom lens is disclosed in Japanese Patent Kokai No. 2004-354871. Such a zoom lens realizes a high variable magnification ratio of about 3 and favorable optical properties and is capable of attaining a slim design of the digital camera adopting the zoom lens.